Posted by
Kyle on
.
Solve and simplify
(3+9i)(125i)
8+6i/75i

1 out of 2 
Sofia,
Rewrite as:
3+9i12+5i
Add like terms:
9+14i is your answer.

math 
Reiny,
for the 2nd, multiply top and bottom by 7+5i
(8+6i)/(75i) * (7+5i)/(7+5i)
=(56 + 40i + 42i + 30i^2)/(48  25i^2)
= (26 + 82i)/73 . remember i^2 = 1